O milho com tolerância ao herbicida glyphosate (Roundup Ready®) (milho RR®) vem sendo cada vez mais empregado, uma vez que propicia o uso deste herbicida para o controle de plantas daninhas. Assim o objetivo do trabalho foi avaliar a tolerância do híbrido 2B810PW (RR2/LL), submetido à aplicação de glyphosate, glufosinate e atrazine, isolados e associados em pós-emergência (V4). O ensaio foi realizado no campo, na safra 2013/14, e o delineamento adotado foi de blocos casualizados, com quatro repetições. Os tratamentos constituíram-se da aplicação de glyphosate (1080 g ha-¹ de equivalente ácido - e.a.), glufosinate (500 g ha-¹ de ingrediente ativo - i.a.), atrazine (2000 g ha-¹ i.a.), glyphosate + glufosinate, glyphosate + atrazine, glufosinate + atrazine, glyphosate + glufosinate + atrazine, além da testemunha sem aplicação. Foram avaliadas fitointoxicação aos 7, 14, 21 e 28 dias após a aplicação (DAA) e índice SPAD, aos 21 e 28 DAA. Também foram avaliadas variáveis relacionadas ao desempenho agronômico: altura, altura de inserção da espiga, diâmetro do colmo, massa de mil grãos e produtividade. Em geral, as variáveis não foram afetadas pelos tratamentos. O híbrido de milho 2B810 PW apresentou-se tolerante, para a aplicação em pós-emergência (V4) dos herbicidas nas doses utilizadas.

-The aim of this study was to evaluate the selectivity of ALS inhibitor herbicides, applied isolated and associated with glyphosate in post-emergence of soybean cultivar presenting the RR/STS technologies. The experimental design was a randomized block with four replications and ten treatments. The treatments consisted of the application of glyphosate and ALS inhibitors herbicides, isolated and associated with glyphosate. The application of treatments occurred in V4 stage of plant development. The evaluation of phytointoxication, SPAD index was conducted, as well as variables related to agronomic performance (height, number of pods per plant, yield and mass of a thousand seeds). Yet additional test with the same cultivar and treatment was conducted in a greenhouse in a completely randomized design with four replications. Soybean cultivar CD 2630 RR/STS presented itself tolerant to application in post-emergence herbicides used alone or combined with glyphosate. Except to metsulfuron-methyl (2.4 g a.i. ha -1 ), associated or not with glyphosate (960 g a.e. ha -1 ).Keywords: sulfonylurea tolerant soybeans, phytointoxication, chemical management, Glycine max. Palavras-chave: soja tolerante as sulfoniluréias, fitointoxicação, manejo químico, Glycine max. RESUMO -O objetivo do presente trabalho foi avaliar a seletividade de herbicidas inibidores da ALS, aplicados isoladamente e associados com glyphosate, em pós-emergência de cultivar de soja contendo as tecnologias RR/STS. O delineamento experimental foi de blocos casualizados, com quatro repetições e dez tratamentos. Os tratamentos foram constituídos da aplicação de glyphosate e herbicidas inibidores da ALS, isolados e associados com glyphosate. A aplicação dos tratamentos

Dicamba is a herbicide with a moderate volatility profile. Such volatility behavior can be significantly diminished with formulation technology and volatilization reducers. The objective of this study was to quantify the volatility potential of dicamba diglycolamine salt (DGA) in a standalone application or in tank mixture with glyphosate (potassium salt) (GK), with and without volatilization reducer (acetic acid—VaporGrip®) from different surfaces. The combination of these products was applied on four different surfaces (glass slides, corn straw, and dry and moist sandy soil) with three replications, and the experiment was duplicated. The application was performed indoors with an automated sprayer. After application, targets were positioned in cartridges containing two filters in series. Cartridges were placed in a vapor collection system that consisted of a chromatographic oven with constant temperature of 40 °C attached to a vacuum pump for 24 h. After this period, liquid samples were obtained from an extraction procedure of filters and surfaces, which corresponded to the volatilized and deposited portions of the herbicides, respectively. The samples were analyzed by liquid chromatography–tandem mass spectrometry (LC-MS/MS). The use of this method provided a rapid and consistent evaluation, in which the treated surface exerts a direct influence on the amount of volatilized dicamba. The mixture of dicamba and glyphosate solutions exhibited different volatility profiles as a function of the treated surfaces. The DGA applied alone had the largest level of volatility when applied on moist soil and the lowest level of volatility in dry soil and straw. The DGA with GK had volatilities similar in dry soil, wet soil and straw. The volatility reducer in the tank mixture was effective in reducing DGA dicamba volatilization, regardless of the sprayed surface and the tank mixture, making the application of dicamba safer from the volatilization standpoint.

The goal was to evaluate the tolerance of maize hybrids 2B810 PW and 30F35 HR to herbicides applied alone and in combination. Trials were carried out in the field in a randomized block design with four replicates. The treatments were three herbicides, alone or in combination, in addition to the control. Herbicides were: atrazine (2000 g ai ha-1); nicosulfuron (50 g ai ha-1) and glyphosate (1080 g ae ha-1). Crop injury was evaluated at 7, 14, 21, and 28 days after application and also SPAD index, height, ear height, stem diameter, 1000-grain weight, and yield. In general, the variables were not affected by the treatments. Hybrids 2B810 PW and 30F35 HR showed tolerance to the application in post-emergence (V4) of the herbicides used.